Data demodulator of a receiving apparatus for spread spectrum communication
US5383220A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 13, 1994 |
| Grant date | Jan 17, 1995 |
| Priority date | — |
| Expiry date | Apr 13, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/707
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A data demodulator of a receiving apparatus for spread spectrum communication for removing the phase difference remaining after detection for improving reception quality. In-phase and quadrature axis received signals are multiplied by pseudonoise codes PNI(t) and PNQ(t) and the results are averaged by averaging sections for calculating the correlation. By performing correlation processing, .rho.kO cos .theta., -.rho.O sin .theta., .rho.kO sin .theta., and .rho.kO cos .theta. are output when the amplitude of receive path signal is assumed to be .rho., the phase difference to be .theta., and a proportional constant to be kO. These signals are multiplied by in-phase and quadrature axis received signals and the results are added by adders, thereby removing the effect of the phase difference .theta.. The signal is used for data demodulation and data recovery circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.